The UK's banks say they have not decided whether to move operations outside of the UK after Brexit, a top banker has said.
Anthony Browne, chief executive of the British Bankers' Association, told a House of Lords EU committee that banks are pondering moves abroad.
He called for current arrangements to stay as close as possible to those now in place with the European Union.
He said transitional arrangements with the EU were needed.
Mr Browne added that would remove uncertainty and ease pressure on banks, while also avoiding "cliff edge" disruption to markets.
"There is a 'wait and see' at the moment," he said.
He was giving public evidence on the subject of "Brexit: Financial Services" to the EU Financial Affairs Sub-Committee.
The Lords were told that once Britain has begun formal talks to withdraw from the EU, departure will take place after two years.
Brexit will occur even if no new trade deal has been agreed, unless all EU member states agree to extend the negotiation period, the Lords heard.
"We think there should be some form of transitional arrangements," Mr Browne said.